| 摘要 |
The drill bit (210) includes a sensor device which responds to the electromagnetic environment around it. The sensor device comprises at least one magnetic field sensor (121), preferably a semiconductor magnetic field sensor. The drill bit also includes a permanent magnet (128N, 128S) or electromagnet. Independent claims are also included for the following: (A) Drilling system comprising the drill bit and an evaluation device for generating a signal corresponding to the detection of ferromagnetic material close to the drill bit; (B) Drilling system comprising the drill bit, an excitation circuit for at least one coil (222) used to induce eddy currents in the material around it and an evaluation device for determining eddy current loss by the coil; (C) Drilling system for grounded objects, especially for demolition work, comprising a drill bit which is supplied with a voltage and whereby a leakage current via the drill bit and surrounding material is measured; (D) Drilling system for demolition work, comprising a drill bit connected to an alternating voltage or current source, whereby the energy emitted by the bit by radiation is measured; and (E) Drilling method comprising providing the drive device for the drill bit with one or more (preferably 2-4) signal routes. |
